from __future__ import unicode_literals

import frappe, json, os
from frappe.utils import flt, cstr
from erpnext.controllers.taxes_and_totals import get_itemised_tax
from frappe import _
from six import string_types
from frappe.utils.file_manager import save_file, remove_file
from frappe.desk.form.load import get_attachments
from erpnext.regional.italy import state_codes


def update_itemised_tax_data(doc):
	if not doc.taxes: return

	itemised_tax = get_itemised_tax(doc.taxes)

	for row in doc.items:
		tax_rate = 0.0
		if itemised_tax.get(row.item_code):
			tax_rate = sum([tax.get('tax_rate', 0) for d, tax in itemised_tax.get(row.item_code).items()])

		row.tax_rate = flt(tax_rate, row.precision("tax_rate"))
		row.tax_amount = flt((row.net_amount * tax_rate) / 100, row.precision("net_amount"))
		row.total_amount = flt((row.net_amount + row.tax_amount), row.precision("total_amount"))

@frappe.whitelist()
def export_invoices(filters=None):
	saved_xmls = []

	invoices = frappe.get_all("Sales Invoice", filters=get_conditions(filters), fields=["*"])

	for invoice in invoices:
		attachments = get_e_invoice_attachments(invoice)
		saved_xmls += [attachment.file_name for attachment in attachments]

	zip_filename = "{0}-einvoices.zip".format(frappe.utils.get_datetime().strftime("%Y%m%d_%H%M%S"))

	download_zip(saved_xmls, zip_filename)


@frappe.whitelist()
def prepare_invoice(invoice, progressive_number):
	#set company information
	company = frappe.get_doc("Company", invoice.company)

	invoice.progressive_number = progressive_number
	invoice.unamended_name = get_unamended_name(invoice)
	invoice.company_data = company
	company_address = frappe.get_doc("Address", invoice.company_address)
	invoice.company_address_data = company_address

	#Set invoice type
	if invoice.is_return and invoice.return_against:
		invoice.type_of_document = "TD04" #Credit Note (Nota di Credito)
		invoice.return_against_unamended =  get_unamended_name(frappe.get_doc("Sales Invoice", invoice.return_against))
	else:
		invoice.type_of_document = "TD01" #Sales Invoice (Fattura)

	#set customer information
	invoice.customer_data = frappe.get_doc("Customer", invoice.customer)
	customer_address = frappe.get_doc("Address", invoice.customer_address)
	invoice.customer_address_data = customer_address

	if invoice.shipping_address_name:
		invoice.shipping_address_data = frappe.get_doc("Address", invoice.shipping_address_name)

	if invoice.customer_data.is_public_administration:
		invoice.transmission_format_code = "FPA12"
	else:
		invoice.transmission_format_code = "FPR12"

	invoice.e_invoice_items = [item for item in invoice.items]
	tax_data = get_invoice_summary(invoice.e_invoice_items, invoice.taxes)
	invoice.tax_data = tax_data

	#Check if stamp duty (Bollo) of 2 EUR exists.
	stamp_duty_charge_row = next((tax for tax in invoice.taxes if tax.charge_type == "Actual" and tax.tax_amount == 2.0 ), None)
	if stamp_duty_charge_row:
		invoice.stamp_duty = stamp_duty_charge_row.tax_amount

	for item in invoice.e_invoice_items:
		if item.tax_rate == 0.0 and item.tax_amount == 0.0 and tax_data.get("0.0"):
			item.tax_exemption_reason = tax_data["0.0"]["tax_exemption_reason"]

	customer_po_data = {}
	for d in invoice.e_invoice_items:
		if (d.customer_po_no and d.customer_po_date
			and d.customer_po_no not in customer_po_data):
			customer_po_data[d.customer_po_no] = d.customer_po_date

	invoice.customer_po_data = customer_po_data

	return invoice

def get_conditions(filters):
	filters = json.loads(filters)

	conditions = {"docstatus": 1}

	if filters.get("company"): conditions["company"] = filters["company"]
	if filters.get("customer"): conditions["customer"] =  filters["customer"]

	if filters.get("from_date"): conditions["posting_date"] = (">=", filters["from_date"])
	if filters.get("to_date"): conditions["posting_date"] = ("<=", filters["to_date"])

	if filters.get("from_date") and filters.get("to_date"):
		conditions["posting_date"] = ("between", [filters.get("from_date"), filters.get("to_date")])

	return conditions

#TODO: Use function from frappe once PR #6853 is merged.
def download_zip(files, output_filename):
	from zipfile import ZipFile

	input_files = [frappe.get_site_path('private', 'files', filename) for filename in files]
	output_path = frappe.get_site_path('private', 'files', output_filename)

	with ZipFile(output_path, 'w') as output_zip:
		for input_file in input_files:
			output_zip.write(input_file, arcname=os.path.basename(input_file))

	with open(output_path, 'rb') as fileobj:
		filedata = fileobj.read()

	frappe.local.response.filename = output_filename
	frappe.local.response.filecontent = filedata
	frappe.local.response.type = "download"

def get_invoice_summary(items, taxes):
	summary_data = frappe._dict()
	for tax in taxes:
		#Include only VAT charges.
		if tax.charge_type == "Actual":
			continue

		#Charges to appear as items in the e-invoice.
		if tax.charge_type in ["On Previous Row Total", "On Previous Row Amount"]:
			reference_row = next((row for row in taxes if row.idx == int(tax.row_id or 0)), None)
			if reference_row:
				items.append(
					frappe._dict(
						idx=len(items)+1,
						item_code=reference_row.description,
						item_name=reference_row.description,
						description=reference_row.description,
						rate=reference_row.tax_amount,
						qty=1.0,
						amount=reference_row.tax_amount,
						stock_uom=frappe.db.get_single_value("Stock Settings", "stock_uom") or _("Nos"),
						tax_rate=tax.rate,
						tax_amount=(reference_row.tax_amount * tax.rate) / 100,
						net_amount=reference_row.tax_amount,
						taxable_amount=reference_row.tax_amount,
						item_tax_rate={tax.account_head: tax.rate},
						charges=True
					)
				)

		#Check item tax rates if tax rate is zero.
		if tax.rate == 0:
			for item in items:
				item_tax_rate = item.item_tax_rate
				if isinstance(item.item_tax_rate, string_types):
					item_tax_rate = json.loads(item.item_tax_rate)

				if item_tax_rate and tax.account_head in item_tax_rate:
					key = cstr(item_tax_rate[tax.account_head])
					if key not in summary_data:
						summary_data.setdefault(key, {"tax_amount": 0.0, "taxable_amount": 0.0,
							"tax_exemption_reason": "", "tax_exemption_law": ""})

					summary_data[key]["tax_amount"] += item.tax_amount
					summary_data[key]["taxable_amount"] += item.net_amount
					if key == "0.0":
						summary_data[key]["tax_exemption_reason"] = tax.tax_exemption_reason
						summary_data[key]["tax_exemption_law"] = tax.tax_exemption_law

			if summary_data == {}: #Implies that Zero VAT has not been set on any item.
				summary_data.setdefault("0.0", {"tax_amount": 0.0, "taxable_amount": tax.total,
					"tax_exemption_reason": tax.tax_exemption_reason, "tax_exemption_law": tax.tax_exemption_law})

		else:
			item_wise_tax_detail = json.loads(tax.item_wise_tax_detail)
			for rate_item in [tax_item for tax_item in item_wise_tax_detail.items() if tax_item[1][0] == tax.rate]:
				key = cstr(tax.rate)
				if not summary_data.get(key): summary_data.setdefault(key, {"tax_amount": 0.0, "taxable_amount": 0.0})
				summary_data[key]["tax_amount"] += rate_item[1][1]
				summary_data[key]["taxable_amount"] += sum([item.net_amount for item in items if item.item_code == rate_item[0]])

			for item in items:
				key = cstr(tax.rate)
				if item.get("charges"):
					if not summary_data.get(key): summary_data.setdefault(key, {"taxable_amount": 0.0})
					summary_data[key]["taxable_amount"] += item.taxable_amount

	return summary_data

#Preflight for successful e-invoice export.
def sales_invoice_validate(doc):
	#Validate company
	if doc.doctype != 'Sales Invoice':
		return

	if not doc.company_address:
		frappe.throw(_("Please set an Address on the Company '%s'" % doc.company), title=_("E-Invoicing Information Missing"))
	else:
		validate_address(doc.company_address)

	company_fiscal_regime = frappe.get_cached_value("Company", doc.company, 'fiscal_regime')
	if not company_fiscal_regime:
		frappe.throw(_("Fiscal Regime is mandatory, kindly set the fiscal regime in the company {0}")
			.format(doc.company))
	else:
		doc.company_fiscal_regime = company_fiscal_regime

	doc.company_tax_id = frappe.get_cached_value("Company", doc.company, 'tax_id')
	doc.company_fiscal_code = frappe.get_cached_value("Company", doc.company, 'fiscal_code')
	if not doc.company_tax_id and not doc.company_fiscal_code:
		frappe.throw(_("Please set either the Tax ID or Fiscal Code on Company '%s'" % doc.company), title=_("E-Invoicing Information Missing"))

	#Validate customer details
	customer = frappe.get_doc("Customer", doc.customer)

	if customer.customer_type == "Individual":
		doc.customer_fiscal_code = customer.fiscal_code
		if not doc.customer_fiscal_code:
			frappe.throw(_("Please set Fiscal Code for the customer '%s'" % doc.customer), title=_("E-Invoicing Information Missing"))
	else:
		if customer.is_public_administration:
			doc.customer_fiscal_code = customer.fiscal_code
			if not doc.customer_fiscal_code:
				frappe.throw(_("Please set Fiscal Code for the public administration '%s'" % doc.customer), title=_("E-Invoicing Information Missing"))
		else:
			doc.tax_id = customer.tax_id
			if not doc.tax_id:
				frappe.throw(_("Please set Tax ID for the customer '%s'" % doc.customer), title=_("E-Invoicing Information Missing"))

	if not doc.customer_address:
	 	frappe.throw(_("Please set the Customer Address"), title=_("E-Invoicing Information Missing"))
	else:
		validate_address(doc.customer_address)

	if not len(doc.taxes):
		frappe.throw(_("Please set at least one row in the Taxes and Charges Table"), title=_("E-Invoicing Information Missing"))
	else:
		for row in doc.taxes:
			if row.rate == 0 and row.tax_amount == 0 and not row.tax_exemption_reason:
				frappe.throw(_("Row {0}: Please set at Tax Exemption Reason in Sales Taxes and Charges".format(row.idx)),
					title=_("E-Invoicing Information Missing"))

	for schedule in doc.payment_schedule:
		if schedule.mode_of_payment and not schedule.mode_of_payment_code:
			schedule.mode_of_payment_code = frappe.get_cached_value('Mode of Payment',
				schedule.mode_of_payment, 'mode_of_payment_code')

#Ensure payment details are valid for e-invoice.
def sales_invoice_on_submit(doc, method):
	#Validate payment details
	if get_company_country(doc.company) not in ['Italy',
		'Italia', 'Italian Republic', 'Repubblica Italiana']:
		return

	if not len(doc.payment_schedule):
		frappe.throw(_("Please set the Payment Schedule"), title=_("E-Invoicing Information Missing"))
	else:
		for schedule in doc.payment_schedule:
			if not schedule.mode_of_payment:
				frappe.throw(_("Row {0}: Please set the Mode of Payment in Payment Schedule".format(schedule.idx)),
					title=_("E-Invoicing Information Missing"))
			elif not frappe.db.get_value("Mode of Payment", schedule.mode_of_payment, "mode_of_payment_code"):
				frappe.throw(_("Row {0}: Please set the correct code on Mode of Payment {1}".format(schedule.idx, schedule.mode_of_payment)),
					title=_("E-Invoicing Information Missing"))

	prepare_and_attach_invoice(doc)

def prepare_and_attach_invoice(doc, replace=False):
	progressive_name, progressive_number = get_progressive_name_and_number(doc, replace)

	invoice = prepare_invoice(doc, progressive_number)
	invoice_xml = frappe.render_template('erpnext/regional/italy/e-invoice.xml', context={"doc": invoice}, is_path=True)
	invoice_xml = invoice_xml.replace("&", "&amp;")

	xml_filename = progressive_name + ".xml"
	return save_file(xml_filename, invoice_xml, dt=doc.doctype, dn=doc.name, is_private=True)

@frappe.whitelist()
def generate_single_invoice(docname):
	doc = frappe.get_doc("Sales Invoice", docname)


	e_invoice = prepare_and_attach_invoice(doc, True)

	return e_invoice.file_name

@frappe.whitelist()
def download_e_invoice_file(file_name):
	content = None
	with open(frappe.get_site_path('private', 'files', file_name), "r") as f:
		content = f.read()

	frappe.local.response.filename = file_name
	frappe.local.response.filecontent = content
	frappe.local.response.type = "download"

#Delete e-invoice attachment on cancel.
def sales_invoice_on_cancel(doc, method):
	if get_company_country(doc.company) not in ['Italy',
		'Italia', 'Italian Republic', 'Repubblica Italiana']:
		return

	for attachment in get_e_invoice_attachments(doc):
		remove_file(attachment.name, attached_to_doctype=doc.doctype, attached_to_name=doc.name)

def get_company_country(company):
	return frappe.get_cached_value('Company', company, 'country')

def get_e_invoice_attachments(invoice):
	if not invoice.company_tax_id:
		return []

	out = []
	attachments = get_attachments(invoice.doctype, invoice.name)
	company_tax_id = invoice.company_tax_id if invoice.company_tax_id.startswith("IT") else "IT" + invoice.company_tax_id

	for attachment in attachments:
		if attachment.file_name and attachment.file_name.startswith(company_tax_id) and attachment.file_name.endswith(".xml"):
			out.append(attachment)

	return out

def validate_address(address_name):
	fields = ["pincode", "city", "country_code"]
	data = frappe.get_cached_value("Address", address_name, fields, as_dict=1) or {}

	for field in fields:
		if not data.get(field):
			frappe.throw(_("Please set {0} for address {1}".format(field.replace('-',''), address_name)),
				title=_("E-Invoicing Information Missing"))

def get_unamended_name(doc):
	attributes = ["naming_series", "amended_from"]
	for attribute in attributes:
		if not hasattr(doc, attribute):
			return doc.name

	if doc.amended_from:
		return "-".join(doc.name.split("-")[:-1])
	else:
		return doc.name

def get_progressive_name_and_number(doc, replace=False):
	if replace:
		for attachment in get_e_invoice_attachments(doc):
			remove_file(attachment.name, attached_to_doctype=doc.doctype, attached_to_name=doc.name)
			filename = attachment.file_name.split(".xml")[0]
			return filename, filename.split("_")[1]

	company_tax_id = doc.company_tax_id if doc.company_tax_id.startswith("IT") else "IT" + doc.company_tax_id
	progressive_name = frappe.model.naming.make_autoname(company_tax_id + "_.#####")
	progressive_number = progressive_name.split("_")[1]

	return progressive_name, progressive_number

def set_state_code(doc, method):
	if doc.get('country_code'):
		doc.country_code = doc.country_code.upper()

	if not doc.get('state'):
		return

	if not (hasattr(doc, "state_code") and doc.country in ["Italy", "Italia", "Italian Republic", "Repubblica Italiana"]):
		return

	state_codes_lower = {key.lower():value for key,value in state_codes.items()}

	state = doc.get('state','').lower()
	if state_codes_lower.get(state):
		doc.state_code = state_codes_lower.get(state)
